Dancers from the Philadelphia Ballet perform for Pope Francis (R) as he attends the Festival of Families rally in Philadelphia, Pennsylvania September 26, 2015. (Photo by Brian Snyder/Reuters)

Porters carry the carcasses of a shark (L) and a Marlin (R) to the local market in Hamarweyne near the port of Mogadishu on the Indian Ocean coast on November 18, 2014 in the Somalia capital as fishermen bring in their catch. (Photo by Mohamed Abdiwahab/AFP Photo)

American supermodel Bella Hadid (R) holds onto her friend's leg for dear life in the second decade of January 2023. (Photo by bellahadid/Instagram)

Friends (L-R) Katherine Olson, Olivia Carroll and Maron Ross take a memory during the 148th running of the Preakness Stakes at Pimlico Race Course on May 20, 2023. (Photo by Jonathan Newton/The Washington Post)

Cadets prepare to take part in a full dress rehearsal for the upcoming Republic Day parade, in Chennai on January 24, 2024. (Photo by R. Satish Babu/AFP Photo)

A police officer detains a person during protest by supporters of Pakistan's former Prime Minister Imran Khan against his arrest, in Karachi, Pakistan, 09 May 2023. Khan, the chairman of Pakistan Tehreek-e-Insaf, was taken into custody by the National Accountability Bureau (NAB) on 09 May outside the Islamabad High Court, where he had arrived to appeal for bail in multiple cases filed against him. The arrest came after Khan's ouster from power in April 2020 following a failed vote of confidence in parliament. (Photo by Rehan Khan/EPA)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)